Storm drains provide an important function in directing rain and storm water from residential, commercial and industrial areas. Typically a storm drain includes a compartment or a housing structure that sits below grade and typically includes a bottom, a surrounding side wall, an inlet and an outlet. Typically the inlet of a storm drain is provided along a street or roadway curb. Storm drains are strategically located with respect to the surrounding elevation of land and paved areas such that water resulting from storm or rain showers will gravitate to the storm drain inlet. Of course, rain and storm water will be directed into the inlet but also trash, debris, leaves, limbs and other vegetation tend to be caught up in the flow of water and are also directed into the storm drains. This trash, debris and other unwanted objects and materials can cause serious problems. First, the debris, trash and the like tend to accumulate in the bottom of the storm drain and interfere with the flow of water through the storm drain. Eventually this debris and trash enters the storm drain outlet and is flushed into streams, creeks, rivers and other waterways.
One of the challenges in filtering debris and trash from storm water passing through the storm drain is designing a filter system or assembly that is compatible with the storm drain. An examination of storm drains across the United States reveals that their designs are not consistent. They are not all the same size and the layout and design vary from location to location. Specifically, it is not uncommon to find storm drains where the side walls and the bottom are not uniform. For example, it is common practice to provide a depression in the bottom of the storm drain in the vicinity of the outlet. This depression channels or feeds water into the outlet. This depression, however, will vary from storm drain to storm drain in terms of length, width, and depth. This is problematic because in order to efficiently filter the water flowing to and through the outlet, the filter applied must conform to these irregularities and provide screening for the entire volume of water being directed to the outlet.
Therefore, there has been and continues to be a need for a filtering system or filter assembly for a storm drain that is sufficiently flexible in design such that the filter assembly as a whole is able to conform to irregularities in the structure of the storm drain and efficiently filter the entire flow of water directed to the outlet.